In a known vacuum switching chamber of this type, the two cap-like metal parts, which are composed of copper, and one of which forms the actual switching area for the stationary contact tip and the axially moving contact tip, are connected in a vacuum-tight manner at the end of the tubular wall region to the annular insulator. In each case, they are connected by blade soldering. In order to allow this known vacuum switching chamber to reliably switch short-circuit currents in the range from 50 to 100 kA while having axial and radial dimensions which are as small as possible, a folding bellows is soldered by one of its ends to the contact bolts of the moving contact tip, and in the immediate vicinity of the latter, and is surrounded concentrically by the annular insulator; a cap-like protective shield at the bottom of the moving contact tip in this case protects the folding bellows against electrical loads. This vacuum interrupter has no special shield for protection of the inner isolating gap which is formed by the annular insulator, since a relatively broad end surface of the annular insulator faces away from the contact region. The power current connections of this known vacuum switching chamber are—as normal—in the form of bolts, which pass axially through the respective cap-like metal part. The two contact tips are normally in the form of pot-type contacts; however, other known contact shapes may also be used (DE 44 22 316 A1). Another known contact shape is, for example, spiral contacts (spiral petal contacts) with, in particular, flat, plate-like contact electrodes, which are provided with slits running inward from the outer circumference. These slits may each comprise a straight section and a hole which passes through the contact surface (EP 0 532 513 B1).
Vacuum interrupters are already known as switching elements for low-voltage contactors, in which the folding bellows forms a part of the outer surface of the enclosure and in this case connected in a vacuum-tight manner on one side to the power current connection of the moving contact bolt and on the other side, at the end, to a short tubular insulator (DE 37 09 585 C2). A folding bellows may in this case be connected by blade soldering both to the insulator and to the power current connection of the moving contact bolt (DE 195 10 850 C1).
Furthermore, vacuum switches are known for shunt operation of D.C. electrolysis cells, which have to switch a current of about 4000 A with a switching voltage of about 4 volts, and in which cylindrical contacts are incorporated in planar, conductive end plates, in order to allow the switch to be electrically connected to electrical connecting rails. In this case, each contact is soldered in a vacuum-tight manner via a corrugated membrane in the form of a disk to an insulating ring, which is arranged concentrically about the switching path. In one case, a holder for a shield in the form of a short piece of tubing is incorporated in the soldered joint, (which is produced as a blade soldered joint by means of an axial annular flange) between the membranes and the insulating ring (U.S. Pat. No. 4,216,360 A, DE 29 44 286 A).
For vacuum switches which are used as vacuum contactors for low voltage, it is also known for a membrane which is provided with two deep, concentrically arranged, corrugations also to be used instead of a folding bellows as a sprung closure part for the switching chamber, which allows the moving contact tip to move. The two parts of the transversely split power current connecting bolt of the moving contact are soldered to this region of the membrane in the central region of the membrane, which is planar (DE 27 25 092 A1).